1. Field of the Invention
The present invention relates to an antifeedant and a contact insecticide comprising the components contained in Cyperaceae species.
2. Description of the Prior Art
In agriculture, plant damage due to insects is unavoidable. In the old days, pyrethroid was used as a natural insecticide. Nowadays, pyrethrin, which is a component of pyrethroid, is synthesized and utilized as an insecticide. In addition to these, nicotine sulfate and machine oil are insecticides obtained from natural substances. However, no effective insecticides have been obtained from natural substances, except for pyrethroid and its component, pyrethrin.
On the other hand, the use of powerful synthesized pesticides (a herbicide, an insecticide, an anti-microbial agent) tend to cause the appearance of resistant organisms. Erigeron annuus PERS and the like, which are resistant to paraquat are ones which acquired the resistance at an early stage. Concerning insects, especially among those having a short generation time, this phenomenon is confirmed in the early stages. Because of the appearance of these organisms having resistance, it becomes necessary to develop new treatment agents having novel functions. It is also essential for those who raise crops to control harmful insects with agents, and the use of powerful pesticides for that purpose results in the disturbance of the ecosystem of a treated area. For example, the use of insecticides against one harmful insect, can cause the explosive breeding of another harmful insect.
A study directed to the use of antifeedant has been conducted in order to protect the plants from the harmful insects. Particularly, a study directed to juglon, which is contained in a walnut, as a natural antifeedant has been conducted. However, juglon has a strong anti-breeding effect on the plants and therefore it has not been put to practical use.
We have carried out an intensive study directed to the development of a safe, natural antifeedant, insecticide and pesticide which contains no halogen, and which does not cause development of resistance in harmful insects and which does not disturb the ecosystem and as a result, the present invention was accomplished.
A method for protecting the plants from the harmful insects by preventing them from eating the plants was studied, and we found that scabequinone, remirol, cyperaquinone and the derivatives thereof, which are present in Cyperaceae species, are antifeedants. The present invention is based on the findings.